Two types of control devices have been proposed. In a first example, components are fixed with screws (see, for example, Patent Document 1). In a second example, components are mounted from one direction without using screws (see, for example, Patent Document 2).
Referring to FIG. 11, the first existing example is described. As shown in FIG. 11, a control device is constructed by placing a printed circuit board 102 on a base 103, screwing a screw 119 into a through hole 113 in the printed circuit board 102 and a screw hole 106 in a board mounting boss 107 so as to fasten the printed circuit board 102 to the base 103, joining a fitting protrusion in an inner cover mounting boss 109 of the base 103 to a fitting recess in a boss 116 on an inner cover 104, pinching the printed circuit board 102 with the inner cover 104, fastening the inner cover 104 with screws 120, and covering the entire base 103 with a cover 105.
Referring to FIGS. 12 and 13, the second existing example is described. As shown in FIG. 12, an existing control device is assembled as follows. First, an LCD case 210 is fixed to a back surface or another part of a printed circuit board 202 with connecting pieces 211c by soldering or the like. Next, as indicated by arrow A in FIG. 13, a side plate 213 of an LCD cover 212 is hooked to bent portions 211b of a side plate 211 of the LCD case 210, an LCD cover 212 is rotated around the hooked portion as indicated by arrow B in the figure, and notches 213a in another side plate 213 of the LCD cover 212 are engaged with other bent portions 211a. By moving the LCD cover 212 in this state, the bent portions 211a and the notches 213a are engaged with each other, and the LCD case 210 is engaged with the LCD cover 212, whereby assembly is completed.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-244648 (p. 3, FIG. 1)    Patent Document 2: Japanese Unexamined Patent Application Publication No. 63-000198 (p. 2, FIGS. 1 and 2)